Koa Middleware

Koa is a lightweight web framework for Node.js, created by the Express team. It's minimal (provides only essentials), middleware-first, and built on async/await (not callbacks). A Koa app is a composition of middleware functions—each middleware has access to a context object (request + response) and can execute code before/after downstream middleware. Koa provides routing (via koa-router), body parsing, static file serving, and a clean API for building REST APIs and web servers.